1. Field of the Invention
This invention relates to a self-timer device for a camera.
2. Description of the Prior Art
A timer device is disclosed in Japanese Laid-open Patent Application No. 93130/1978. In this device, a set member for rendering a self-timer circuit capable of counting time is movable between an operable position in which the self-timer is capable of counting time and an inoperable position in which the self-timer is incapable of counting time. The set member is designed so that it is held in the operable position during the time counting of the self-timer and is brought to the inoperable position with the operation of the shutter release system after termination of its time counting function. This device obviates the possibility of the photographer neglecting to return the set member from the operable position to the inoperable position after self-timer photography and thereby prevents self-timer photography from taking place against his will during the next photographic operation.
However, by operatively associating the set member with the shutter release system, the transmission system from the shutter release button to the shutter driving system must perform the work of moving the set member. Accordingly, if, for example, the set member is operatively associated with the release button, a greater force is required to depress the release button than if the set member was not associated with it and also, where the release button is an electromagnetic release device, the attraction of the magnet must be increased and this causes an undesirable increase in the bulk of the device.
In order that the set member may be moved by the shutter driving system of the shutter release transmission system, it is necessary to cause a force for moving the set member to be additionally accumulated in a shutter driving spring, and the force accumulated in the shutter driving spring must be adjusted to a predetermined magnitude in order that the shutter may be moved at a stable speed. However, adding the force for moving the set member to the accumulated force makes it difficult to achieve such adjustment. Also, if the set member is moved by this accumulated force during the release of the accumulated shutter driving spring, namely, during the movement of the shutter, the movement of the shutter will become irregular thus adversely affecting the film exposure.